Segmentation and Volume Estimation of the Habenula Using Deep Learning in Patients With Depression

Background

The habenula is involved in the pathophysiology of depression. However, its small structure limits the accuracy of segmentation methods, and the findings regarding its volume have been inconsistent. This study aimed to create a highly accurate habenula segmentation model using deep learning, test its generalizability to clinical magnetic resonance imaging, and examine differences between healthy participants and patients with depression.

Methods

This multicenter study included 382 participants (patients with depression: N = 234, women 47.0%; healthy participants: N = 148, women 37.8%). A 3-dimensional residual U-Net was used to create a habenula segmentation model on 3T magnetic resonance images. The reproducibility and generalizability of the predictive model were tested on various validation cohorts. Thereafter, differences between the habenula volume of healthy participants and that of patients with depression were examined.

Results

A Dice coefficient of 86.6% was achieved in the derivation cohort. The test-retest dataset showed a mean absolute percentage error of 6.66, indicating sufficiently high reproducibility. A Dice coefficient of >80% was achieved for datasets with different imaging conditions, such as magnetic field strengths, spatial resolutions, and imaging sequences, by adjusting the threshold. A significant negative correlation with age was observed in the general population, and this correlation was more pronounced in patients with depression (p < 10-7, r = -0.59). Habenula volume decreased with depression severity in women even when the effects of age and scanner were excluded (p = .019, η2 = 0.099).

Conclusions

Habenula volume could be a pathophysiologically relevant factor and diagnostic and therapeutic marker for depression, particularly in women.

SGLT2 inhibitor versus carbohydrate-restricted isocaloric diet: reprogramming substrate oxidation in type 2 diabetes

OBJECTIVE

Based on the whole-body energy metabolism and insulin action, the difference between increased excretion of carbohydrate in urine by SGLT2i and reduced same amount of oral carbohydrate intake are scarce. This study aimed to compare the effect of carbohydrate availability with reduced oral intake (carbohydrate-restricted isocaloric diet: CRIC diet) or lost in urine, as urinary glucosuria on sodium/glucose cotransporter-2 inhibitor (SGLT2i) treatment, focus on the insulin requirement and the macronutrient oxidation within insulin treated type 2 diabetes.

METHODS

This is randomized 3-arm open-label prospective study. Subjects treated with titrated basal-bolus insulin regimen subsequent to three diet regimens, control diet (CON), administration of canagliflozin 100 mg/day to CON (SGLT2i), or CRIC diet, with a week admission to the endocrinology ward followed by 12 weeks outpatients' management. The main outcome measures including the total insulin dose (TID) required to achieve euglycemia, fasting and postprandial energy expenditure (EE) and respiratory quotient (RQ) at 1-week and 12-week.

RESULTS

We enrolled 23 patients with type 2 diabetes (male/female: 14/9, age: 53.6 ± 14.2 years, body mass index: 26.9 ± 4.8 kg/m², HbA1c: 12.5 ± 1.6%). The TID was similar with CON and SGLT2i at both 1 and 12-weeks. Although comparable net carbohydrate availability in SGLT2i and CRIC groups, the TID was significantly higher in the CRIC (p = 0.02) compare to the SGLT2i at both 1 and 12-weeks. Fasting EE was similar in all groups, postprandial EE was significantly elevated in the SGLT2i and CRIC groups compared to the CON group (p = 0.03 and 0.04). Compare to the CON, lower basal fasting RQ (p = 0.049) and decreased delta-RQ (postprandial RQ/fasting RQ) indicated continuous lipid substrate utilization in the SGLT2i (p = 0.04) and CRIC (p = 0.03) groups.

CONCLUSION

The CRIC diet resulted in a similar fasting and postprandial EE and substrate oxidation compared to the SGLT2i. The increased insulin requirement in the CRIC diet indicates that a relatively highly lipid and protein consumption, compared to the SGLT2i and CON, may influence insulin requirement.

SWI by 7T MR Imaging for the Microscopic Imaging Diagnosis of Astrocytic and Oligodendroglial Tumors

BACKGROUND AND PURPOSE

Despite advances in molecular imaging, preoperative diagnosis of astrocytomas and oligodendrogliomas can be challenging. In the present study, we assessed whether 7T SWI can be used to distinguish astrocytomas and oligodendrogliomas and whether malignant grading of gliomas is possible.

MATERIALS AND METHODS

7T SWI was performed on 21 patients with gliomas before surgery with optimization for sharp visualization of the corticomedullary junction. Scoring for cortical thickening and displacement of medullary vessels, characteristic of oligodendroglial tumors, and cortical tapering, characteristic of astrocytic tumors, was performed. Additionally, characteristics of malignancy, including thickening of the medullary veins, the presence of microbleeds, and/or necrosis were scored.

RESULTS

Scoring for oligodendroglial (highest possible score, +3) and astrocytic (lowest score possible, -3) characteristics yielded a significant difference between astrocytomas and oligodendrogliomas (mean, -1.93 versus +1.71, P < .01). Scoring for malignancy was significantly different among the World Health Organization grade II (n = 10), grade III (n = 4), and grade IV (n = 7) tumors (mean, 0.20 versus 1.38 versus 2.79). Cortical thickening was observed significantly more frequently in oligodendrogliomas (P < .02), with a sensitivity of 71.4% and specificity of 85.7%; observation of tapering of the cortex was higher in astrocytomas (P < .01) with a sensitivity of 85.7% and specificity of 100%.

CONCLUSIONS

Visualization of the corticomedullary junction by 7T SWI was useful in distinguishing astrocytomas and oligodendrogliomas. Observation of tapering of the cortex was most sensitive and specific for diagnosing astrocytomas. Reliably predicting malignant grade was also possible by 7T SWI.

P-763 effect of duration of cryo-storage of vitrified embryos on obstetric and perinatal outcomes

Study question

Does the duration of cryo-storage of vitrified embryos affect obstetric and perinatal outcomes?

Summary answer

Duration of cryo-storage with an open vitrification system did not affect obstetric and perinatal outcomes.

What is known already

Frozen-thawed blastocyst transfer has been performed widely with improvement of embryo culture conditions and cryopreservation techniques. Although blastocyst vitrification has become an essential method to improve clinical outcomes of IVF, there has been little study into the relationship between a long duration of cryo-storage in liquid nitrogen and obstetric and perinatal outcomes.

Study design, size, duration

This retrospective study was conducted at Kyono ART Clinic from January 2007 to December 2020. This study includes a total of 1053 singletons derived from 2461 frozen-thawed blastocyst transfers in 2461 patients. Steel’s multiple comparison test was performed for clinical and perinatal outcomes with cases of cryo-storage of less than 3 months as a control group. P &lt; 0.05 was considered statistically significant.

Participants/materials, setting, methods

The subjects are patients who underwent their first single frozen-thawed blastocyst transfer (FBT) with an open vitrification system. Females &gt;40 years old at cryopreservation and those who underwent preimplantation genetic testing were excluded. According to cryo-storage duration, patients were grouped as follows: group A, 0-3 months (1255 cycles); group B, 3-6 months (1008 cycles); group C, 6-12 months (162 cycles), group D, 12-24 months (36 cycles).

Main results and the role of chance

Both the mean maternal age at blastocyst cryopreservation (A: 33.7±3.6, B: 34.1±3.5, C: 34.8±3.2, D: 35.1±3.3) and the mean maternal age at FBT (A: 33.8±3.6, B: 34.4±3.5, C: 35.5±3.1, D: 36.4±3.3) in groups B, C, and D were significantly higher compared to those in group A.. There was no significant difference in the survival rate after blastocyst thawing [A: 97.4% (1256/1290), B: 98.3% (1010/1027), C: 99.4% (163/164), D: 97.2% (35/36)]. The pregnancy rate in group C was significantly lower compared to group A [A: 60.0% (752/1254), B: 61.4% (619/1008), C: 48.1% (78/162), D: 63.9% (23/36)] The gestational age of group C was significantly lower compared to group A (A: 39.5±1.8, B: 39.4±1.8, C: 38.4±3.1, D: 39.8±1.6), but there were no significant differences in live birth weight or height. There were no significant differences in congenital abnormality rate [A: 1.3% (7/541), B: 2.5% (11/440), C: 1.8% (1/56), D: 0.0% (0/16)], placental abnormalities such as placenta previa [A: 1.3% (7/541), B: 1.6% (7/440), C: 1.8% (1/56), D: 0.0% (0/16)], perinatal abnormalities such as hypertensive disorders of pregnancy or gestational diabetes [A: 6.1% (33/541), B: 8.6% (38/440), C: 1.8% (1/56), D: 6.3% (1/16)] among the four groups.

Limitations, reasons for caution

We could not provide sufficient information on confounding factors such as smoking habits, and the sample size was too small for multivariate analysis. The safety of longer storage will need to be verified as this has not been clarified in this study.

Wider implications of the findings

The pregnancy rate in group C was significantly lower than that in group A, but the effect was small: 0.065, power of 0.78. Our data suggested that the duration of cryopreservation with an open vitrification system in liquid nitrogen did not affect obstetric or perinatal outcomes.

Trial registration number

not applicable

New polymethylmethacrylate membrane, NF-U, improves nutritional status and reduces patient-reported symptoms in older dialysis patients

Introduction

We previously reported the nutritional advantage of polymethylmethacrylate (PMMA) membranes to prevent the progression of malnutrition in dialysis patients. In this study, we examined whether a new PMMA dialyzer, NF-U, has advantages to improve the nutritional condition, patient-reported symptoms, and other clinical parameters in older dialysis patients.

Methods

We selected ten older chronic dialysis patients who were treated with NF-U for improving their worsening nutritional parameters and retrospectively evaluated nutrition and patient-reported symptoms. Patient-reported symptoms were surveyed by our original questionnaire including 20 items of symptom.

Results

Serum albumin concentration, geriatric nutritional risk index, and percent creatinine generation rate increased from 3.01 ± 0.16 to 3.25 ± 0.17 g/dL, 87.7 ± 5.8 to 91.4 ± 6.2, 100.2 ± 21.6 to 111.9 ± 20.9% at 1 and 4 months after switching to NF-U, respectively. For patient-reported outcomes, fatigue and the total score of patient-reported outcomes were improved after switching to NF-U.

Conclusion

Our results suggest that NF-U is a good choice for older dialysis patients to ameliorate their nutritional status and patient-reported outcomes.

P1073NF-U OF A NEW POLYMETHYLMETHACRYLATE MEMBRANE IMPROVES THE NUTRITIONAL STATUS AND PATIENT-REPORTED SYMPTOMS OF ELDER DIALYSIS PATIENTS

Background and Aims

Malnutrition is the most powerful prognostic factor in dialysis patients, and elder dialysis patients have a higher risk of malnutrition because of multiple comorbidities and daily inactivity. Hence, it is very important to set up a dialysis prescription for preventing progression of malnutrition. We reported nutritional advantage of polymethylmethacrylate (PMMA) membrane for preventing dialysis patients from the progression of malnutrition in the previous report. NF-U has been developed with better hemocompatibility and lesser albumin leakage during the dialysis session than conventional PMMA membranes. We studied additional advantages of NF-U on the nutritional status, patient-reported symptoms and other clinical parameters in elder dialysis patients.

Method

This study was a retrospective one. 10 elder chronic dialysis patients of greater than 75 years old were enrolled into the study; 5 males and 5 females, the mean age was 82.8 years old, and the average dialysis vintage was 11.2 years. NF-U were installed because of low albuminemia, dry weight (DW) loss and other signs of malnutrition. The previous membrane materials were polyether polymer alloy (6), vitamin E coated polysulfone (1), on-line HDF with polyethersulfone (2) and polysulfone (1). On-line HDF were performed in predilution with the substitution volume of 12L/hr. During the observation period the dialysis prescription except dialysis membrane was not changed.

Serum albumin, β2MG, CRP, nPCR, GNRI, ％CGR, DW, CTR were compared one month and four month after the replacement with NF-U. In consideration of the seasonal variation of nutritional status, DW and CTR were compared with that of one year before the study. The changes in body composition were analyzed by Inbody770® (Inbody Japan, Tokyo, Japan)at three months before and after the replacement with NF-U. We also evaluated patient-reported subjective symptoms by our original tool as “Patient-oriented Dialysis (POD)” system three months before and after NF-U installation.

Results

Serum albumin increased from 3.0g/dl to 3.3g/dl. GNRI increased from 87.7 to 91.4. %CGR increased from 91.9% to 102.8%. No significant changes were observed in β2MG, CRP and nPCR. Although DW had continuously decreased from 52.7kg to 51.7kg before NF-U installation, DW increased from 52.0kg to 52.7kg by NF-U. CTR did not change. Muscle volume and body fat mass also increased. Regarding subjective symptoms, total POD score was significantly improved and especially dialysis related fatigue was remarkably reduced by NF-U.

Conclusion

The current study clearly showed that NF-U of a new PMMA membrane improved the nutritional status of elder dialysis patients with higher risk of malnutrition although the study was a limited retrospective one. Furthermore, NF-U also improved patient-reported subjective symptoms such as fatigue which was reported as a mortality risk factor and the most important patient’s outcome. We have not yet established a golden standard or parameter to set up dialysis prescriptions properly to elder dialysis patients. However, improvement of nutritional status and fatigue are one of the most important parameters to expect better outcome of them. We conclude that NF-U should be one of the best choices to treat elder dialysis patients.

Neuronal hypertrophy dampens neuronal intrinsic excitability and stress responsiveness during chronic stress

KEY POINTS

The hypothalamic-pituitary-adrenal (HPA) axis habituates to repeated stress exposure. We studied hypothalamic corticotropin-releasing hormone (CRH) neurons that form the apex of the HPA axis in a mouse model of stress habituation using repeated restraint. The intrinsic excitability of CRH neurons decreased after repeated stress in a time course that coincided with the development of HPA axis habituation. This intrinsic excitability plasticity co-developed with an expansion of surface membrane area, which increased a passive electric load and dampened membrane depolarization in response to the influx of positive charge. We report a novel structure-function relationship for intrinsic excitability plasticity as a neural correlate for HPA axis habituation.

ABSTRACT

Encountering a stressor immediately activates the hypothalamic-pituitary-adrenal (HPA) axis, but this stereotypic stress response also undergoes experience-dependent adaptation. Despite the biological and clinical importance, how the brain adjusts stress responsiveness in the long term remains poorly understood. We studied hypothalamic corticotropin-releasing hormone neurons that form the apex of the HPA axis in a mouse model of stress habituation using repeated restraint. Using patch-clamp electrophysiology in acute slices, we found that the intrinsic excitability of these neurons substantially decreased after daily repeated stress in a time course that coincided with their loss of stress responsiveness in vivo. This intrinsic excitability plasticity co-developed with an expansion of surface membrane area, which increased a passive electric load, and dampened membrane depolarization in response to the influx of positive charge. Multiphoton imaging and electron microscopy revealed that repeated stress augmented ruffling of the plasma membrane, suggesting an ultrastructural plasticity that may efficiently accommodate the membrane area expansion. Overall, we report a novel structure-function relationship for intrinsic excitability plasticity as a neural correlate for adaptation of the neuroendocrine stress response.

Risk model for severe postoperative complications after total pancreatectomy based on a nationwide clinical database

BACKGROUND

Total pancreatectomy is required to completely clear tumours that are locally advanced or located in the centre of the pancreas. However, reports describing clinical outcomes after total pancreatectomy are rare. The aim of this retrospective observational study was to assess clinical outcomes following total pancreatectomy using a nationwide registry and to create a risk model for severe postoperative complications.

METHODS

Patients who underwent total pancreatectomy from 2013 to 2017, and who were recorded in the Japan Society of Gastroenterological Surgery and Japanese Society of Hepato-Biliary-Pancreatic Surgery database, were included. Severe complications at 30 days were defined as those with a Clavien-Dindo grade III needing reoperation, or grade IV-V. Occurrence of severe complications was modelled using data from patients treated from 2013 to 2016, and the accuracy of the model tested among patients from 2017 using c-statistics and a calibration plot.

RESULTS

A total of 2167 patients undergoing total pancreatectomy were included. Postoperative 30-day and in-hospital mortality rates were 1·0 per cent (22 of 2167 patients) and 2·7 per cent (58 of 167) respectively, and severe complications developed in 6·0 per cent (131 of 2167). Factors showing a strong positive association with outcome in this risk model were the ASA performance status grade and combined arterial resection. In the test cohort, the c-statistic of the model was 0·70 (95 per cent c.i. 0·59 to 0·81).

CONCLUSION

The risk model may be used to predict severe complications after total pancreatectomy.

Whole hepatic lipid volume quantification and color mapping by multi-slice and multi-point magnetic resonance imaging

AIM

Current approaches for hepatic steatosis assess only a small point within the liver and might cause inaccuracy for longitudinal observation. We aimed to establish a reliable non-invasive method for whole hepatic lipid content evaluation.

METHODS

A total of 52 patients with hepatic steatosis underwent liver biopsy. Hepatic lipid content was assessed by Dixon in-phase/out-of-phase magnetic resonance imaging and proton magnetic resonance spectroscopy. Using multi-slice and multi-point magnetic resonance imaging, we calculated the lipid intensity of every voxel throughout the liver and showed the color-mapped lipid distributions. This new analysis could also quantify the whole hepatic lipid and whole liver volumes absolutely. The diagnostic performance of hepatic lipid content between the new analysis and proton magnetic resonance spectroscopy methods was compared by receiver operating characteristic curve analysis referring to the steatosis scores of the liver biopsy.

RESULTS

Areas under the receiver operating characteristic for the diagnosis of steatosis scores ≥1, ≥2, and ≥3 using magnetic resonance imaging and proton magnetic resonance spectroscopy were 0.86 (95% confidence interval [CI] 0.70-1.00) and 0.98 (95% CI 0.93-1.00), 0.94 (95% CI 0.87-1.00) and 0.93 (95% CI 0.86-1.00), and 0.95 (95% CI 0.89-1.00) and 0.97 (95% CI 0.93-1.00), respectively, showing comparable diagnostic accuracies. However, color mapping showed some inconsistencies between the methods.

CONCLUSIONS

We described a non-invasive and repeatable evaluation method of whole hepatic lipid accumulation with absolute quantification and color mapping. Hepatic steatosis was accurately evaluated regardless of heterogeneous lipid accumulation. The whole hepatic lean volume, reflecting the hepatic parenchymal condition, can also be determined by this method.

PRDM14 promotes malignant phenotype and correlates with poor prognosis in colorectal cancer

BACKGROUND

Emerging evidence suggests that stemness in cancer cells is a cause of drug resistance or metastasis and is an important therapeutic target. PR [positive regulatory domain I-binding factor 1 (PRDI-BF1) and retinoblastoma protein-interacting zinc finger gene (RIZ1)] domain containing 14 (PRDM14), that regulates pluripotency in primordial germ cell, has reported the overexpression and function of stemness in various malignancies, suggesting it as the possible therapeutic target. However, to our knowledge, there have been no reports on the expression and function of PRDM14 in colorectal cancer (CRC). Therefore, we investigated the expression and the role of PRDM14 in CRC.

METHODS

We performed immunohistochemistry evaluations and assessed PRDM14 expression on 414 primary CRC specimens. Colon cancer cell lines were subjected to functional and stemness assays in vitro and in vivo.

RESULTS

We found that PRDM14 positive staining exhibited heterogeneity in the CRC primary tumor, especially at the tumor invasion front. The aberrant expression of PRDM14 at the invasion front was associated with lymph node metastasis and disease stage in patients with CRC. Furthermore, the multivariate analysis revealed high PRDM14 expression as an independent prognostic factor in the patients with Stage III CRC. Overexpression of PRDM14 enhanced the invasive, drug-resistant and stem-like properties in colon cancer cells in vitro and tumorigenicity in vivo.

CONCLUSION

Our findings suggest that PRDM14 is involved in progression and chemoresistance of CRC, and is a potential prognostic biomarker and therapeutic target in the CRC patients.

Sustained fasting glucose oxidation and postprandial lipid oxidation associated with reduced insulin dose in type 2 diabetes with sodium-glucose cotransporter 2 inhibitor: A randomized, open-label, prospective study

AIMS/INTRODUCTION

Hyperglycemia impairs energy substrate oxidation as a result of glucotoxicity. We examined whether the reduction of plasma glucose using a sodium-glucose cotransporter 2 inhibitor, in inpatient diabetes management, has any effect on: (i) treatment period and basal-bolus dosage of insulin that achieve euglycemia; (ii) fasting/postprandial energy expenditure (EE); and (iii) energy substrate oxidation.

MATERIALS AND METHODS

This was a randomized, open-label, 7-day prospective study. Participants were type 2 diabetes patients with hyperglycemia, aged >20 years, with glycated hemoglobin >10%, daily mean preprandial blood glucose >11 mmol/L (200 mg/dL) and no previous antidiabetic medication. A total of 18 type 2 diabetes patients were randomized (1:1) to basal-bolus insulin titration algorithm (INS) alone or INS + dapagliflozin 5 mg/day (INS/DAPA). The main outcome measures were total daily insulin dose to achieve euglycemia, as well as EE and respiratory quotient during fasting and postprandial states, measured by indirect calorimetry.

RESULTS

The rate of euglycemia was higher in the INS/DAPA compared with INS group (100 vs 55.6%, P = 0.04), whereas the total daily dose of insulin was 19% lower and was accompanied by a decreased basal-bolus ratio (P = 0.02). Fasting and postprandial EE elevation were similar in both groups. The post-treatment fasting respiratory quotient significantly increased in the INS/DAPA group (0.72 ± 0.05 vs 0.79 ± 0.08, P = 0.04), and the postprandial respiratory quotient elevation was abolished; the opposite trend was observed in the INS group (P < 0.02).

CONCLUSIONS

INS/DAPA sustained fasting carbohydrate oxidation, postprandial lipid-derived EE (failed to increase carbohydrate-derived EE) and reduced basal insulin requirement might be related to further bodyweight loss.

CLINICAL TRIAL REGISTRY

National University Hospital Medical Information Network UMIN000018997.

Development of canine X-chromosome inactivation pattern analysis for the detection of cell clonality by incorporating the examination of the SLIT and NTRK-like family member 4 (SLITRK4) gene

X-chromosome inactivation pattern (XCIP) analysis can be used to assess the clonality of cell populations of various origin by distinguishing the methylated X chromosome from the unmethylated X chromosome. In this study, the utility of XCIP analysis was improved by incorporating the examination of AC dinucleotide repeats in SLIT and NTRK-like family member 4 (SLITRK4) gene into the previously reported CAG repeat examination of androgen receptor (AR) gene in dogs. The rate of heterozygosity when both genes were analysed (125/150, 83.3%) was higher than AR gene examination alone (86/150, 57.3%). Blood samples from heterozygous dogs in either AC-1 or AC-2 of SLITRK4 gene were examined for the corrected inactivation allele ratio (CIAR), resulting in the determination of a reference range of CIAR <3.8 in non-neoplastic cell/tissue samples. Using this analytical method, 49% (21/43) of neoplastic tissue samples from dogs showed a CIAR >3.8, indicating the presence of a clonal population. Through the present study, the availability of canine XCIP analysis was improved by incorporating the examination of the SLITRK4 gene, providing a highly useful laboratory examination system for the detection of the clonality of various cell/tissue samples in dogs.

Mechanisms of sleep deprivation-induced hepatic steatosis and insulin resistance in mice

Sleep deprivation is associated with increased risk for type 2 diabetes mellitus. However, the underlying mechanisms of sleep deprivation-induced glucose intolerance remain elusive. The aim of this study was to investigate the mechanisms of sleep deprivation-induced glucose intolerance in mice with a special focus on the liver. We established a mouse model of sleep deprivation-induced glucose intolerance using C57BL/6J male mice. A single 6-h sleep deprivation by the gentle handling method under fasting condition induced glucose intolerance. Hepatic glucose production assessed by a pyruvate challenge test was significantly increased, as was hepatic triglyceride content (by 67.9%) in the sleep deprivation group, compared with freely sleeping control mice. Metabolome and microarray analyses were used to evaluate hepatic metabolites and gene expression levels and to determine the molecular mechanisms of sleep deprivation-induced hepatic steatosis. Hepatic metabolites, such as acetyl coenzyme A, 3β-hydroxybutyric acid, and certain acylcarnitines, were significantly increased in the sleep deprivation group, suggesting increased lipid oxidation in the liver. In contrast, fasted sleep-deprived mice showed that hepatic gene expression levels of elongation of very long chain fatty acids-like 3, lipin 1, perilipin 4, perilipin 5, and acyl-CoA thioesterase 1, which are known to play lipogenic roles, were 2.7, 4.5, 3.7, 2.9, and 2.8 times, respectively, those of the fasted sleeping control group, as assessed by quantitative RT-PCR. Sleep deprivation-induced hepatic steatosis and hepatic insulin resistance seem to be mediated through upregulation of hepatic lipogenic enzymes.

Organelle Optogenetics: Direct Manipulation of Intracellular Ca2+ Dynamics by Light

As one of the ubiquitous second messengers, the intracellular Ca²⁺, has been revealed to be a pivotal regulator of various cellular functions. Two major sources are involved in the initiation of Ca²⁺-dependent signals: influx from the extracellular space and release from the intracellular Ca²⁺ stores such as the endoplasmic/sarcoplasmic reticulum (ER/SR). To manipulate the Ca²⁺ release from the stores under high spatiotemporal precision, we established a new method termed “organelle optogenetics.” That is, one of the light-sensitive cation channels (channelrhodopsin-green receiver, ChRGR), which is Ca²⁺-permeable, was specifically targeted to the ER/SR. The expression specificity as well as the functional operation of the ER/SR-targeted ChRGR (ChRGR_ER) was evaluated using mouse skeletal myoblasts (C2C12): (1) the ChRGR_ER co-localized with the ER-marker KDEL; (2) no membrane current was generated by light under whole-cell clamp of cells expressing ChRGR_ER; (3) an increase of fluorometric Ca²⁺ was evoked by the optical stimulation (OS) in the cells expressing ChRGR_ER in a manner independent on the extracellular Ca²⁺ concentration ([Ca²⁺]_o); (4) the ΔF/F₀ was sensitive to the inhibitor of sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) and (5) the store-operated Ca²⁺ entry (SOCE) was induced by the OS in the ChRGR_ER-expressing cells. Our organelle optogenetics effectively manipulated the ER/SR to release Ca²⁺ from intracellular stores. The use of organelle optogenetics would reveal the neuroscientific significance of intracellular Ca²⁺ dynamics under spatiotemporal precision.

Targeted expression of step-function opsins in transgenic rats for optogenetic studies

Rats are excellent animal models for experimental neuroscience. However, the application of optogenetics in rats has been hindered because of the limited number of established transgenic rat strains. To accomplish cell-type specific targeting of an optimized optogenetic molecular tool, we generated ROSA26/CAG-floxed STOP-ChRFR(C167A)-Venus BAC rats that conditionally express the step-function mutant channelrhodopsin ChRFR(C167A) under the control of extrinsic Cre recombinase. In primary cultured cortical neurons derived from this reporter rat, only Cre-positive cells expressing ChRFR(C167A) became bi-stable, that is, their excitability was enhanced by blue light and returned to the baseline by yellow~red light. In bigenic pups carrying the Phox2B-Cre driver, ChRFR(C167A) was specifically expressed in the rostral parafacial respiratory group (pFRG) in the medulla, where endogenous Phox2b immunoreactivity was detected. These neurons were sensitive to blue light with an increase in the firing frequency. Thus, this transgenic rat actuator/reporter system should facilitate optogenetic studies involving the effective in vivo manipulation of the activities of specific cell fractions using light of minimal intensity.

A transportation network for human ovarian tissue is indispensable to success for fertility preservation

PURPOSE

The purpose of this study was to examine the efficacy of an ovarian tissue transportation network for fertility preservation (FP) for cancer patients in Japan.

METHODS

PubMed was searched for papers on transportation of human ovarian tissue for FP. We analyzed population, area, number of cancer patients for ovarian tissue cryopreservation (OTC), quality control/assessment and safety, cost of a cryopreservation center for the building for 30 years, and medical fees of cancer patients (operation, cryopreservation, and storage of ovarian tissue).

RESULTS

More than twenty babies have been born in Denmark and Germany through a transportation system. Up to 400 new patients a year need OTC. The fees for removal, cryopreservation, and storage for 5 years, and transplantation of ovarian tissue are around €5,000, €4,000, and €5,000, respectively. It costs more than €5 million to establish and maintain one cryopreservation center for 30 years. If we have a few cryopreservation centers in Japan, we can cryopreserve 400 patients' ovarian tissue per year by safer slow freezing and maintain quality control/assessment. We need to lighten the patients' burden for easy to use FP by a government subsidy and medical insurance coverage.

CONCLUSIONS

This model has been termed the Danish model ("the woman stays - the tissue moves"). This is truly patient-centered medicine. We can have maximum effects with the minimum burden. A transportation network like those of Denmark and Germany is the best strategy for FP in Japan. It may be the best system for cancer patients, medical staff, and the Ministry of Health, Labor, and Welfare.

A case of idiopathic normal pressure hydrocephalus in an elder diabetic patient

The clinical entity idiopathic normal pressure hydrocephalus (iNPH) is characterized by dementia, urinary incontinence, gait ataxia. An 80-year old man with a past history of Type 2 diabetes mellitus admitted to our hospital. Combination of twice Aspart and Aspart premixed30/70 insulin were used. Although, he was unable to inject insulin by himself recently. On physical examination, he walked in a mildly wide based manner. According to his family, urinary incontinence was existed. Laboratory data were as follows: Postrandial blood glucose 243 mg/dl and glycated hemoglobin 8.0% (NGSP). Brain magnetic resonance imaging (MRI) scans showed thinning of the corpus callosum with enlargement of the lateral ventricles on a colonal image. Evan's ratio was 0.29. The revised version of Hasegawa's Dementia scale (HDS-R) was 10. The patient showed no evidence a related antecedent event, such as head trauma, intracerebral hemorrhage and meningitis. Thus, he was diagnosed as having possible Idiopathic normal pressure hydrocephalus (iNPH). The following several psychological tests and walking test were applied. Before and after the tap, he was evaluated using the HDS-R, Mini mental state examination (MMSE), Timed Up and Go test (TUG). Insulin was replaced by glargine, and Sitagliptin was added. On the 31 day, the patient underwent Ventriculo-perioneal shunt. Laboratoly data and memory impairment were also improved. 8 month's later, HbA1c was 7.5%. iNPH occurs in the elderly and is characterized by a clinical triad of gait disturbance, urinary incontinence and dementia. In the present case, thinning of the corpus callosum with enlargement of the lateral ventricles was detected by MRI. 49% of iNPH patients had Diabetes mellitus. However, we were unable to detect a relationship iNPH and Diabetes mellitus. Cognitive impairment may interfere with the insulin therapy. In the present case, failure of insulin self-injection was the first clinical sign to appear. We were able to reduce dose of insulin. We conclude that iNPH is a treatable disorder, especially when treatment is started early in the course of the disease.

Acute suppurative thyroiditis in infected thyroid cyst in an adult patient under hemodialysis

Acute suppurative thyroiditis (AST) accompanied by an abscess is a rare clinical case. Hemodialysis patients are at risk for infections. Sepsis mortality was from 100 to 300 times higher for chronic dialysis patients than that for the general public. Thus, special care should be taken against infection in patients under hemodialysis.

A Chimera Na+-Pump Rhodopsin as an Effective Optogenetic Silencer

With the progress of optogenetics, the activities of genetically identified neurons can be optically silenced to determine whether the neurons in question are necessary for the network performance of the behavioral expression. This logical induction is expected to be improved by the application of the Na⁺ pump rhodopsins (NaRs), which hyperpolarize the membrane potential with negligible influence on the ionic/pH balance. Here, we made several chimeric NaRs between two NaRs, KR2 and IaNaR from Krokinobacter eikastus and Indibacter alkaliphilus, respectively. We found that one of these chimeras, named I₁K₆NaR, exhibited some improvements in the membrane targeting and photocurrent properties over native NaRs. The I₁K₆NaR-expressing cortical neurons were stably silenced by green light irradiation for a certain long duration. With its rapid kinetics and voltage dependency, the photoactivation of I₁K₆NaR would specifically counteract the generation of action potentials with less hyperpolarization of the neuronal membrane potential than KR2.

Time-of-Flight MR Angiography of Portal System and Collaterals in Portal Hypertension Using a 2-DFT Fast Spoiled Gradient Recalled Steady-State Precession Technique

MR angiographic examinations were performed in 26 patients. Approximately 30 contiguous fast spoiled GRASS images (8.1/3.1/30°, TR/TE/flip angle) were acquired during single breath-holding for about 35 s, and then new images were reconstructed with maximum intensity projection technique. Spoiled GRASS images (40/12/40) of 2 to 3 slices were taken during breath-holding for about 13 s, and these processes were repeated to obtain about 30 individual images for conventional MR angiography. The new MR angiograms were compared quantitatively and qualitatively with conventional MR angiograms with arterial portography as the gold standard. The new MR angiograms could visualize blood vessels with smooth margins, and provided almost the same anatomic information about the portal vein and collateral vessels as the conventional MR angiograms. Contrast-to-noise ratios between the portal or hepatic vein and liver parenchyma were significantly higher with fast spoiled GRASS images. The new MR angiograms using fast spoiled GRASS images provided useful diagnostic mapping of the collateral venous pathways within a shorter examination time.

Efficacy and Safety of Salmeterol/fluticasone Combination Therapy in Infants and Preschool Children with Asthma Insufficiently Controlled by Inhaled Corticosteroids

BACKGROUND

Clinical evidences of inhaled salmeterol/fluticasone propionate combination (SFC) therapy are insufficient in early childhood asthma.

OBJECTIVES

To examine the effects of SFC50, a combination product of salmeterol xinafoate (50 μg/day) and fluticasone propionate (100 μg/day), in infants and preschool children with asthma.

METHODS

The study was conducted at 31 sites in Japan. 35 patients (6 months to 5 years old) with asthma insufficiently controlled by inhaled corticosteroids (100 μg/day) were initiated to treat with SFC50 twice a day for 12 weeks with pressurized metered dose inhalers. The efficacy of SFC50 was assessed using nighttime sleep disorder score as the primary endpoint and the other efficacy measurements. The safety measurement included the incidences of adverse event (AE).

RESULTS

Mean patient age was 3.1 years, and 94.2% had mild-to-moderate persistent asthma (atopic type: 65.7%). Nighttime sleep disorder scores, assessed by a nighttime sleep diary, significantly decreased after treatment with SFC50 throughout the study period (p<0.01). SFC50 also significantly improved other efficacy outcomes including asthma symptom score, frequency of short-acting beta-agonist treatment, frequency of unscheduled visits to clinic, frequency of exacerbation due to virus infection, asthma control score and patient QOL score (p<0.01). AEs of cold, upper respiratory inflammation and asthmatic attack occurred in each of the 3 patients (8.6%); however, these were not regarded as treatment-related AEs.

CONCLUSIONS

SFC50 improved nighttime sleep disorder score and other efficacy outcome measures with no safety concerns. The results suggest that SFC50 treatment is useful to control the mild-to-moderate asthma in infant and preschool-aged children.

A Novel Reporter Rat Strain That Conditionally Expresses the Bright Red Fluorescent Protein tdTomato

Despite the strength of the Cre/loxP recombination system in animal models, its application in rats trails that in mice because of the lack of relevant reporter strains. Here, we generated a floxed STOP tdTomato rat that conditionally expresses a red fluorescent protein variant (tdTomato) in the presence of exogenous Cre recombinase. The tdTomato signal vividly visualizes neurons including their projection fibers and spines without any histological enhancement. In addition, a transgenic rat line (FLAME) that ubiquitously expresses tdTomato was successfully established by injecting intracytoplasmic Cre mRNA into fertilized ova. Our rat reporter system will facilitate connectome studies as well as the visualization of the fine structures of genetically identified cells for long periods both in vivo and ex vivo. Furthermore, FLAME is an ideal model for organ transplantation research owing to improved traceability of cells/tissues.

Changes in the Small Intestine of a Cat Associated with Barium Sulphate Following Contrast Radiography

A 7-year-old neutered male domestic short-haired cat that had undergone contrast radiography of the bowel with barium sulphate after acute episodes of vomiting 2 months previously, was presented with chronic vomiting, anorexia and weight loss. Abdominal radiography and ultrasonography revealed residual contrast enhancement and an obstruction of the small intestine. A contracted and stenosed ileum and distal jejunum were identified by exploratory laparotomy and surgically resected; subsequently, the clinical signs resolved. Histopathological examination of the ileum revealed mucosal ulceration with severe submucosal granulation tissue formation associated with scattered foreign crystalline material. Energy-dispersive X-ray spectroscopy revealed that the crystals contained barium sulphate. This is the first report in animals of the rare complication of barium sulphate incorporation into the gastrointestinal mucosa after contrast radiography.

A Phox2b BAC Transgenic Rat Line Useful for Understanding Respiratory Rhythm Generator Neural Circuitry

The key role of the respiratory neural center is respiratory rhythm generation to maintain homeostasis through the control of arterial blood pCO₂/pH and pO₂ levels. The neuronal network responsible for respiratory rhythm generation in neonatal rat resides in the ventral side of the medulla and is composed of two groups; the parafacial respiratory group (pFRG) and the pre-Bötzinger complex group (preBötC). The pFRG partially overlaps in the retrotrapezoid nucleus (RTN), which was originally identified in adult cats and rats. Part of the pre-inspiratory (Pre-I) neurons in the RTN/pFRG serves as central chemoreceptor neurons and the CO₂ sensitive Pre-I neurons express homeobox gene Phox2b. Phox2b encodes a transcription factor and is essential for the development of the sensory-motor visceral circuits. Mutations in human PHOX2B cause congenital hypoventilation syndrome, which is characterized by blunted ventilatory response to hypercapnia. Here we describe the generation of a novel transgenic (Tg) rat harboring fluorescently labeled Pre-I neurons in the RTN/pFRG. In addition, the Tg rat showed fluorescent signals in autonomic enteric neurons and carotid bodies. Because the Tg rat expresses inducible Cre recombinase in PHOX2B-positive cells during development, it is a potentially powerful tool for dissecting the entire picture of the respiratory neural network during development and for identifying the CO₂/O₂ sensor molecules in the adult central and peripheral nervous systems.

Japanese multicenter experience of endoscopic necrosectomy for infected walled-off pancreatic necrosis: The JENIPaN study

BACKGROUND AND STUDY AIMS

Only a few large cohort studies have evaluated the efficacy and safety of endoscopic necrosectomy for infected walled-off pancreatic necrosis (WOPN). Therefore, a multicenter, large cohort study was conducted to evaluate the efficacy and safety of endoscopic necrosectomy and to examine the procedural details and follow-up after successful endoscopic necrosectomy.

PATIENTS AND METHODS

A retrospective review was conducted in 16 leading Japanese institutions for patients who underwent endoscopic necrosectomy for infected WOPN between August 2005 and July 2011. The follow-up data were also reviewed to determine the long-term outcomes of the procedures.

RESULTS

Of 57 patients, 43 (75 %) experienced successful resolution after a median of 5 sessions of endoscopic necrosectomy and 21 days of treatment. Complications occurred in 19 patients (33 %) during the treatment period. Six patients died (11 %): two due to multiple organ failure and one patient each from air embolism, splenic aneurysm, hemorrhage from a Mallory - Weiss tear, and an unknown cause. Of 43 patients with successful endoscopic necrosectomy, recurrent cavity formation was observed in three patients during a median follow-up period of 27 months.

CONCLUSIONS

Endoscopic necrosectomy can be an effective technique for infected WOPN and requires a relatively short treatment period. However, serious complications can arise, including death. Therefore, patients should be carefully selected, and knowledgeable, skilled, and experienced operators should perform the procedure. Further research into safer technologies is required in order to reduce the associated morbidity and mortality.

Japanese multicenter experience of endoscopic necrosectomy for infected walled-off pancreatic necrosis: The JENIPaN study

BACKGROUND AND STUDY AIMS

Only a few large cohort studies have evaluated the efficacy and safety of endoscopic necrosectomy for infected walled-off pancreatic necrosis (WOPN). Therefore, a multicenter, large cohort study was conducted to evaluate the efficacy and safety of endoscopic necrosectomy and to examine the procedural details and follow-up after successful endoscopic necrosectomy.

PATIENTS AND METHODS

A retrospective review was conducted in 16 leading Japanese institutions for patients who underwent endoscopic necrosectomy for infected WOPN between August 2005 and July 2011. The follow-up data were also reviewed to determine the long-term outcomes of the procedures.

RESULTS

Of 57 patients, 43 (75 %) experienced successful resolution after a median of 5 sessions of endoscopic necrosectomy and 21 days of treatment. Complications occurred in 19 patients (33 %) during the treatment period. Six patients died (11 %): two due to multiple organ failure and one patient each from air embolism, splenic aneurysm, hemorrhage from a Mallory - Weiss tear, and an unknown cause. Of 43 patients with successful endoscopic necrosectomy, recurrent cavity formation was observed in three patients during a median follow-up period of 27 months.

CONCLUSIONS

Endoscopic necrosectomy can be an effective technique for infected WOPN and requires a relatively short treatment period. However, serious complications can arise, including death. Therefore, patients should be carefully selected, and knowledgeable, skilled, and experienced operators should perform the procedure. Further research into safer technologies is required in order to reduce the associated morbidity and mortality.

Biocompatibility of predilution on-line hemodiafiltration

In the previous papers, we reported that predilution hemodiafiltration (HDF) has more beneficial effects on dialysis patients than postdilution HDF. The mechanism behind this has not yet been clarified, but some factors could explain the advantage, such as a well-balanced solute removal pattern, reduction in the small nutrient loss and biocompatibility. Generally, the efficacy of small solute and low-molecular-weight protein removal is better in postdilution HDF or hemodialysis than in predilution; however, the more efficient removal does not always lead to the improvement of patients' symptoms and feelings. This issue suggests that the biocompatibility is an essential aspect for evaluating the quality of dialysis modality. There are three possible mechanisms for the advantages of predilution on-line HDF in biocompatibility. First, a large amount of filtrate at the filter could drain away chemical-eluting substances from the dialysis membrane and some reactive proteins. Second, blood dilution could reduce the chance of blood cells to be in close contact with the dialysis membrane surface, and then it could reduce the sequential inflammatory response. Third, blood dilution itself reduces the production of free radicals. We believe the biocompatibility of predilution online HDF is closely related to the improvement of dialysis-related various symptoms.